1. Preheat oven to 350 degrees Fahrenheit. Grease muffin tins.
2. In a small bowl, combine filling ingredients.
3. In another small bowl, combine crumble ingredients.
4. In a large mixing bowl, combine all muffin ingredients and mix until smooth. Fill muffin tins one-third of the way.
5. Place one tablespoon of filling over batter. Cover with batter. Sprinkle crumble over batter and bake for 30 minutes.